"""Widgets shared by the main app and the per-device test benches.

Each of these was hand-rolled several times across the apps, with slightly
different behaviour every time (only one log console bounded its buffer,
only one port picker sorted by device type).
"""

from __future__ import annotations

from PyQt6.QtCore import Qt, pyqtSignal
from PyQt6.QtGui import QFont
from PyQt6.QtWidgets import (
    QComboBox, QGroupBox, QHBoxLayout, QLabel, QPlainTextEdit, QPushButton,
    QVBoxLayout, QWidget,
)

from hardware.serial_util import scored_ports


def mono_font(size: int = 11) -> QFont:
    """Monospace font for numeric read-outs, so columns of digits line up."""
    font = QFont("Menlo")
    font.setStyleHint(QFont.StyleHint.Monospace)
    font.setPointSize(size)
    return font


def set_toggle(btn, checked: bool, text: str, enabled: bool = True):
    """Update a checkable button without re-triggering its toggled signal."""
    btn.blockSignals(True)
    btn.setChecked(checked)
    btn.setText(text)
    btn.setEnabled(enabled)
    btn.blockSignals(False)


class PortSelector(QWidget):
    """Serial port combo + refresh button, likeliest device first."""

    def __init__(self, parent=None):
        super().__init__(parent)
        row = QHBoxLayout(self)
        row.setContentsMargins(0, 0, 0, 0)
        self.combo = QComboBox()
        self.combo.setMinimumWidth(220)
        refresh = QPushButton("⟳")
        refresh.setFixedWidth(30)
        refresh.setToolTip("Rescan serial ports")
        refresh.clicked.connect(self.refresh)
        row.addWidget(self.combo, stretch=1)
        row.addWidget(refresh)
        self.refresh()

    def refresh(self):
        """Repopulate the list, preserving the current selection if present."""
        current = self.current_port()
        self.combo.clear()
        for device, label in scored_ports():
            self.combo.addItem(label, device)
        if self.combo.count() == 0:
            self.combo.addItem("(no serial ports found)", None)
        elif current:
            idx = self.combo.findData(current)
            if idx >= 0:
                self.combo.setCurrentIndex(idx)

    def current_port(self) -> str | None:
        return self.combo.currentData()

    def set_port(self, device: str):
        idx = self.combo.findData(device)
        if idx >= 0:
            self.combo.setCurrentIndex(idx)


class ConnectionBar(QGroupBox):
    """Port picker + connect toggle + status label.

    Emits connect_requested(port) / disconnect_requested(); the owner drives
    the state back through on_connected/on_disconnected/on_failed so the
    button can never disagree with the hardware.
    """

    connect_requested = pyqtSignal(str)
    disconnect_requested = pyqtSignal()

    def __init__(self, title: str = "Connection", parent=None):
        super().__init__(title, parent)
        layout = QVBoxLayout(self)
        self.port_selector = PortSelector()
        layout.addWidget(self.port_selector)

        row = QHBoxLayout()
        self.toggle = QPushButton("Connect")
        self.toggle.setCheckable(True)
        self.toggle.toggled.connect(self._on_toggled)
        self.status = QLabel("Disconnected")
        self.status.setStyleSheet("font-weight: bold;")
        row.addWidget(self.toggle)
        row.addWidget(self.status, stretch=1)
        layout.addLayout(row)

    def _on_toggled(self, checked: bool):
        if checked:
            port = self.port_selector.current_port()
            if not port:
                set_toggle(self.toggle, False, "Connect")
                self.status.setText("No port selected")
                return
            self.toggle.setText("Connecting…")
            self.toggle.setEnabled(False)
            self.connect_requested.emit(port)
        else:
            self.disconnect_requested.emit()

    def on_connected(self, detail: str = "Connected"):
        set_toggle(self.toggle, True, "Disconnect")
        self.status.setText(detail)
        self.status.setStyleSheet("font-weight: bold; color: green;")

    def on_disconnected(self, detail: str = "Disconnected"):
        set_toggle(self.toggle, False, "Connect")
        self.status.setText(detail)
        self.status.setStyleSheet("font-weight: bold;")

    def on_failed(self, message: str):
        set_toggle(self.toggle, False, "Connect")
        self.status.setText(f"Failed: {message}")
        self.status.setStyleSheet("font-weight: bold; color: red;")


class LogConsole(QWidget):
    """Bounded, monospace, auto-scrolling log view with a Clear button.

    The block cap is the point: unbounded QTextEdit logs grew for the whole
    session in every app that hand-rolled one.
    """

    KINDS = {"tx": "→", "rx": "←", "info": "●", "err": "!"}

    def __init__(self, max_blocks: int = 2000, parent=None):
        super().__init__(parent)
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)

        self.view = QPlainTextEdit()
        self.view.setReadOnly(True)
        self.view.setMaximumBlockCount(max_blocks)
        self.view.setFont(mono_font())
        layout.addWidget(self.view)

        row = QHBoxLayout()
        row.addStretch(1)
        clear = QPushButton("Clear")
        clear.clicked.connect(self.view.clear)
        row.addWidget(clear)
        layout.addLayout(row)

    def log(self, message: str, kind: str = "info"):
        self.view.appendPlainText(f"{self.KINDS.get(kind, '●')} {message}")
        self.view.verticalScrollBar().setValue(
            self.view.verticalScrollBar().maximum())


class StatusGrid(QWidget):
    """Label/value rows with consistent ok/warn/error colouring."""

    _COLORS = {"ok": "green", "warn": "#b8860b", "error": "red", "": ""}

    def __init__(self, fields: list[str], parent=None):
        super().__init__(parent)
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        self._values: dict[str, QLabel] = {}
        for name in fields:
            row = QHBoxLayout()
            label = QLabel(f"{name}:")
            value = QLabel("—")
            value.setAlignment(Qt.AlignmentFlag.AlignRight
                               | Qt.AlignmentFlag.AlignVCenter)
            row.addWidget(label)
            row.addWidget(value, stretch=1)
            layout.addLayout(row)
            self._values[name] = value

    def set(self, name: str, text: str, state: str = ""):
        label = self._values.get(name)
        if label is None:
            return
        label.setText(text)
        color = self._COLORS.get(state, "")
        label.setStyleSheet(f"color: {color};" if color else "")